By using (26) , a 600M -byte music CD can be compressed to 50M bytes or less. It can be streamed (downloaded in chunks) so that you can begin listening to the opening bars while the (27) of the file arrives in the background. And, most important, the music files of this kind retain good listening (28) that earlier (29) schemes lacked. That (30) of features makes accessing and distributing music on the web practical for the first time.
A．difference
B．combination
C．addition
D．condition
